Transport device, loading device and method for loading and unloading the transport device

ABSTRACT

A transport device for transporting elongated substrates through a vacuum coating system comprises an essentially rectangular frame and two groups of holding elements, which are rotatably mounted on opposite sides of the frame in such a manner that any pair of opposite holding elements can be connected to both ends of a substrate. Furthermore, at least one retainer bar is provided that is operatively connected to a group of holding elements in such a manner that the holding elements of this group are moveable in order to increase or decrease by choice their distance from the holding elements of the other group. Also provided are a loading and unloading device for loading and unloading the transport device, and a method for loading and unloading the transport device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of German Application No. DE 10 2006048 160.7 filed Oct. 10, 2006, the entire contents of which is herebyincorporated by reference.

BACKGROUND ART

The invention relates to a transport device for elongated substrates, aloading and unloading device and a method for loading and unloading thetransport device.

The German patent application 10 2006 031 826.9, the entire content ofwhich is incorporated in the present application by reference, disclosesa transport device (carrier) for transporting elongated substratesthrough a vacuum coating system, which comprises an essentiallyrectangular frame, which is designed for rotationally positioningholding elements (for example, so-called inserts). The holding elementsare configured in such a manner that they can be connected to onerespective end of an elongated substrate. The substrates with theholding elements, which are arranged on the ends of said substrates, aredisposed in the carrier in such a manner that the ends of the twoholding elements are rotatably mounted on the opposite sides of theframe.

A first subject matter of the present application is an improvement ofthe above-described transport device. Another subject matter of theapplication relates to a loading and unloading device for loading andunloading the transport device. Still another subject matter of theapplication relates to a method for loading and unloading the transportdevice.

BRIEF SUMMARY OF THE INVENTION

The transport device according to the invention for transportingelongated substrates through a vacuum coating system comprises anessentially rectangular frame and two groups of holding elements, whichare rotatably mounted on opposite sides of the frame in such a mannerthat any pair of opposite holding elements can be connected to both endsof a substrate. Furthermore, at least one retainer bar is provided thatis operatively connected to a group of holding elements in such a mannerthat the holding elements of this group are moveable in order toincrease or decrease by choice their distance from the holding elementsof the other group.

The transport device may be used for coating elongated substrates in avacuum coating system and makes it possible to simultaneously exchangeall of the substrates that are held in the transport device. In this waythe exchange of substrates can be automated; and the time required forsaid exchange is significantly decreased. At the same time a fouling ofthe substrates is avoided. Horizontal arrangements of the transportdevice in the vacuum coating system are just as possible as verticalarrangements, where the substrates are transported in an upright mannerthrough the vacuum coating system.

The frame may be made, for example, with interconnected longitudinal andtransverse bars, the information “longitudinal” and “transverse”referring to the position of the respective bar in relation to thearrangement of the elongated substrates inside the transport device.Correspondingly, a longitudinal bar is a frame element, which isoriented parallel to the elongated substrates, whereas a transverse baris arranged orthogonal thereto. As explained below, it is expedient toarrange the transport device inside a vacuum coating system in such amanner that the frame elements, which are referred to here as thelongitudinal bars, are oriented at right angles to the direction oftransport. That is, the transverse bars are arranged parallel to thetransport direction of the substrates. Both the longitudinal bars andalso the transverse bars may be made, for example, from a rectangularhollow profile.

The holding elements may be configured, for example, as rotationallysymmetrical components. One end of the holding element may be configuredconically so that it can mate with the end of the tubular substrate(so-called insert). In order to produce the operative connection withthe retainer bar, the other end of such an insert can exhibit, forexample, a peripheral groove, with which the retainer bar engages andwhich enables the transfer of a force, which acts in the longitudinaldirection of the insert, in order to move the insert of one group inthis direction in order to increase or decrease its distance from theopposite insert of the other group. If, for example, ceramic is chosenas the material for the inserts, then they can be manufactured at a lowcost and without maintenance and are suitable for use at hightemperatures. Other designs of the holding elements, which areconfigured so that they can connect with one end of an elongatedsubstrate, are just as possible and are, therefore, regarded as includedin the claimed subject matter.

Another design of the transport device can provide one retainer bar foreach group of holding elements so that both groups of holding elementscan be moved simultaneously or in succession independently of eachother.

Furthermore, it can be provided that each retainer bar can be releasablyconnected to the frame, so that the position of the holding elements issecured against unintentional displacements, when the transport deviceis populated with the substrates. The releasable connection of theretainer bar can be configured, for example, in such a manner that theretainer bar can be releasably connected to a transverse bar of theframe. Of course, the releasable connection of the retainer bar may alsobe realized with the same effect for the longitudinal bar(s) and is,therefore, included in the technical teaching that is claimed.

In another embodiment of the transport device the retainer bar and theframe exhibit complementary connecting means, which can be selectivelyconnected or released through a movement of the retainer bar in relationto the frame in the normal direction of the plane, which is formed bythe frame. In this design the retainer bar is then moved at right anglesto the longitudinal direction of the substrate, in order to release theinterlocking with the frame and then to move the retainer bar in theplane of the frame, in order to release the substrates from the holdingelements. However, the same effect can be achieved with the connectingmeans, which can be selectively connected or released through a movementof the retainer bar in relation to the frame in the plane, formed by theframe. Therefore, such designs are regarded as included in the transportdevice that is claimed.

The holding elements may be mounted, for example, in openings, which areprovided for them in the transverse bars of the frame. A rotationallysymmetrical holding element of the above-described type may be mountedin a central region without any additional mounting mechanisms in onetransverse bar or in a plurality of transverse bars. That means that thecentral region of the holding element and the opening of the transversebar(s) form the mounting of the holding element in the frame. If, forexample, each side of the frame exhibits two parallel running transversebars, each of which exhibits one opening for each holding element, anespecially stable mounting of the holding element is achieved, since theholding element is actively prevented from tilting owing to thesimultaneous mounting in two transverse bars. The mounting of theholding elements in openings of the transverse bar without anyadditional mounting mechanisms is maintenance-free, can be produced at alow cost and is suitable for the use of the transport device at hightemperatures.

In order to coat elongated, for example tubular, substrates uniformlyand on all sides, at least one drive mechanism for rotating the holdingelements may also be provided. The drive mechanism may comprise, forexample, a drivable cable, which is operatively connected to the holdingelements in such a manner that the friction between the moving cable andthe holding elements sets the holding elements rotating. The cable maybe driven, for example, by means of an electric motor. As alreadyexplained above, in particular in the event that the substrates are tobe rotated during the coating process, it is practical to arrange thetransport device in the vacuum coating system in such a manner that thetransverse bars of the transport device are arranged parallel to thetransport direction of the substrates.

The connection between the frame and the retainer bar may be configured,for example, in such a manner that it may be conjoined by moving theretainer bar in relation to the frame in the normal direction of theplane, formed by the longitudinal and the transverse bars, and may bereleased in the opposite direction. Thus, it is possible to release fromthe frame the retainer bar of a transport device of the described typethat is arranged horizontally in a vacuum coating system by lifting andto connect to the frame by lowering.

The transport device according to the invention enables a simple andautomatic loading and unloading of the frame with elongated substrates.To this end, a method is proposed below that can be carried out in anespecially advantageous manner when used with the loading and unloadingdevice that is also described below.

The method according to the invention for loading and unloading thetransport device with elongated substrates comprises the followingsteps:

-   -   1. releasing the connection between the retainer bar and the        frame,    -   2. moving the retainer bar and the group of holding elements        that are connected to said retainer bar, in order to increase        the distance from the other group of holding elements, until the        holding elements are released from the elongated substrates,    -   3. removing the exposed elongated substrates,    -   4. inserting a new batch of elongated substrates,    -   5. moving the retainer bar and the group of holding elements        that are connected to said retainer bar, in order to decrease        the distance from the other group of holding elements, until the        holding elements are connected with the elongated substrates,    -   6. producing the connection between the retainer bar and the        frame.

When the retainer bar(s) and the frame are connected by a movement inrelation to the normal direction of the plane, formed by the frame,steps 1 and 6 of the above-described method mean that such a movement inrelation to the respective correct direction is carried out. Forexample, in a horizontally arranged transport device this can mean thatthe retainer bar(s) is/are lifted, whereas the frame retains itsposition. In contrast, the technical teaching that is claimed alsoincludes embodiments of the method, wherein the frame is lifted, whereasthe retainer bar retains its position or the retainer bars retain theirposition.

It may be provided in an advantageous manner that prior to the secondstep (that is, before moving the retainer bar in the outward directionin order to increase the distance between the two groups of holdingelements), a storage device (tray) is moved into a position below theframe, so that the substrates are deposited on the storage device. Ifthe connection between the retainer bar and the frame is released, asdescribed above, by lifting the retainer bar, then it is advantageous toalso lift the storage device, so that the substrates are receiveddirectly and do not fall onto the storage device. If a storage device isprovided, it can be provided in an advantageous manner that the thirdstep (that is, the removal of the exposed substrates) consists oflowering the storage device and removing it from its position below theframe.

Similarly, the fourth step (that is, the insertion of a new batch ofsubstrates) may consist of moving a substrate-populated storage deviceinto a position below the frame and optionally lifting; and according tothe fifth step (that is, after moving the retainer bar in the inwarddirection, in order to decrease the distance between both groups ofholding elements), it may be provided that the storage device is loweredand moved away from its position below the frame.

In order to carry out this method, a loading and unloading device isproposed that comprises at least one manipulator with a drive mechanismfor carrying out steps 2 and 5 (that is, for moving the retainer bar inthe inward and outward direction). It can be provided in an advantageousmanner that the manipulator is designed in such a manner that it canalso be moved in the normal direction of the plane, formed by the frame.Thus, it is possible to produce the connection between the retainer barand the frame in cases in which to this end a relative movement in thenormal direction is necessary. For example, the manipulator may bedesigned as a gripper claw, which can be moved in the necessarydirections.

It has proven to be advantageous to embody the manipulator as anoperator fork, which reaches into the retainer bar openings that areprovided for said fork and lifts said retainer bar. Furthermore, it canbe provided in an advantageous manner that the manipulator alsocomprises a holding down device. The holding down device can be arrangedin such a manner that it interacts with the operator fork, thus forminga gripper claw. Then the holding down device holds the retainer bar inposition until the operator fork has reached into the retainer baropenings that are provided for said fork; and then together with theoperator fork, the retainer bar executes the inward or outward movementof the retainer bar as well as optionally the lift movement.

The manipulator is the core element of the claimed loading and unloadingdevice. With its aid the basic functions of the method according to theinvention are implemented, namely the connecting and releasing of theretainer bar from the frame as well as the connecting and releasing ofthe holding elements from the elongated substrates.

As another advantage, the loading and unloading device may exhibit alifting device, which may be configured, for example, in such a mannerthat it serves a dual purpose. On the one hand, the lifting device canserve to position the storage device. That is, it can be used to movethe storage device into a position below the frame or to move thestorage device out from underneath said frame and/or to lift and lowerthe storage device. On the other hand, the lifting device may servesimultaneously to support the free ends of the holding elements, whereasthe retainer bar and the holding elements that are connected to said barare moved outwards or remain in the outward position. The lifting devicemakes sure that, on the one hand, the holding elements are guided and,on the other hand, are not damaged during the inward or outward movementof the retainer bar.

BRIEF SUMMARY OF THE DRAWING FIGURES

The invention is explained below with the aid of one embodiment and therelated drawings.

FIG. 1 A is a perspective view and FIG. 1 B is a partial cross-sectionalview of the construction of the transport device according to theinvention of an advantageous embodiment of the invention; and

FIGS. 2 to 10 depict a plurality of different phases of the methodaccording to the invention, according to a preferred embodiment of themethod.

The drawings in FIGS. 2 to 10 depict half sections of the right side ofthe transport device according to the invention and the loading andunloading device according to the invention, as seen in the direction oftransport.

DETAILED DESCRIPTION

As evident from FIGS. 1 A and 1 B, the transport device of theadvantageous embodiment comprises longitudinal bars 1, transverse bars 5and 5 a, retainer bars 3 and holding elements, which are rotatablymounted in the retainer bars 3 and which are configured assubstrateholding inserts 2 in the embodiment. The longitudinal bars 1 and thetransverse bars 5 and 5 a form a rectangular frame. The inserts 2 arearranged in linear arrays on each side and are connected to the ends ofthe elongated substrates 4, so that they, too, are rotatably mounted.The transverse bars 5 and 5 a exhibit openings 11, in which the inserts2 are mounted. In order to connect the retainer bar 3 to the frame, theretainer bar 3 and the two longitudinal bars 1 exhibit complementaryconnecting means 10, which make possible the releasable conjoiningorthogonal to the plane of the frame. To rotate the inserts 2, a drivemechanism employing a drivable cable 12 in frictional contact withinserts 2 and driven by a drive roller 12 a, may be employed.

The following drawings in FIGS. 2 to 10 show the sequence of steps inwhich a first batch of substrates 4 is removed and then a second batchof substrates 4 is received.

First, as shown in FIG. 2, the transport device according to theinvention is moved into the inventive loading and unloading device, orthe loading and unloading device is moved to the transport device. Thisloading and unloading device comprises a holding down device 6 moveablein a direction normal to the plane of frame 1 by a suitable drivemechanism 6 a, an operator fork 7 moveable in a plane formed by theframe 1 by a suitable drive mechanism 7 c and/or in a direction normalto the plane by a suitable drive mechanism 7 a, and a lifting device 8.

Furthermore, the loading and unloading device according to the inventioncomprises, as shown in FIG. 3, a storage device (tray) 9. The emptystorage device 9 is moved into the loading and unloading device anddeposited on the lifting device 8.

FIG. 4 shows how the lifting device 8 executes together with the storagedevice 9 and the operator fork 7 an upward movement, whereas the holdingdown device 6 remains in its position. The operator fork 7 reaches intoan opening of the retainer bar 3, said opening being provided for saidoperator fork.

After the operator fork 7 has reached into the opening of the retainerbar 3, the operator fork 7 and the holding down device 6 move upwards,in order to release, as shown in FIG. 5, the connection between theretainer bar 3 and the frame 1, 5, 5 a.

Then (FIG. 6) the operator fork 7 and the holding down device 6 movetogether outwards in the direction of the longitudinal bar 1, thusreleasing the connection between the inserts 2 and the substrates 4. Inso doing, the free ends of the inserts 2 are supported by the liftingdevice 8 and the substrates 4 are supported by the storage device 9.

In the next step (FIG. 7) the lifting device 8 and with it the storagedevice 9, which is lying on said lifting device and which has thesubstrates 4, is lowered.

Then (FIG. 8) the operator fork 7, the holding down device 6 and withthem the retainer bar 3 and the inserts 2, which are attached to saidretainer bar, are moved again inwards.

FIG. 9 shows that, following completion of the inward movement, theoperator fork 7, the holding down device 6 and with them the retainerbar 3 and the inserts 2, which are attached to said retainer bar, arelowered. In so doing, the retainer bar 3 is connected to the frame 1, 5,5 a.

As soon as the connection between the retainer bar 3 and the frame 1, 5,5 a is produced, the operator fork 7 is lowered further without theholding down device 6 until said operator fork no longer has anyconnection with the transport device (FIG. 10). The storage device 9 isremoved from the region below the transport device so that the coatedsubstrates 4 are accessible. Then the now empty transport device may bepopulated with new substrates 4.

In the figures the design features of the transport device and theloading and unloading device are extremely simplified and schematized.In a real vacuum coating system, two loading and unloading devices,which are identical in construction, are arranged expediently. Inparticular, a first loading and unloading device is arranged at thebeginning of the vacuum coating system, in order to charge the systemwith substrates which are to be coated; and a second loading andunloading device is arranged at the end of the vacuum coating system, inorder to be able to remove the coated substrates from the system. Bothloading and unloading devices exhibit an identical construction. Theloading process takes place in the reverse order of sequence to theabove-described unloading process.

LIST OF REFERENCE NUMERALS

-   1 longitudinal bar-   2 holding element, insert-   3 retainer bar-   4 substrate-   5 transverse bar-   5 a transverse bar-   6 holding down device-   7 operator fork-   8 lifting device-   9 storage device, tray-   10 connecting means-   11 opening

1. Transport device for transporting elongated substrates having twoends through a vacuum coating system, comprising an essentiallyrectangular frame, a first group and a second group of linearly arrayedsubstrate holding inserts, rotatably mounted on opposite sides of theframe, defining mutually opposed pairs of substrate holding inserts,each pair of substrate holding inserts being connected to both ends of arespective intermediate substrate during substrate transport, and, atleast one retainer bar operatively connected to the first group ofinserts in such a manner that the inserts of the first group aremoveable in order to increase or decrease their distance from theinserts of the second group.
 2. Transport device, as claimed in claim 1,wherein the at least one retainer bar comprises a retainer bar providedfor each group of inserts.
 3. Transport device, as claimed in claim 1,wherein the at least one retainer bar is releasably connected to theframe.
 4. Transport device, as claimed in claim 3, wherein the at leastone retainer bar is releasably connected to the frame by complementaryconnecting means, which can be selectively connected or released througha movement of the retainer bar in relation to the frame in a directionnormal to a plane of the frame.
 5. Transport device, as claimed in claim1, wherein the at least one retainer bar is releasably connected to alongitudinal bar of the frame.
 6. Transport device, as claimed in claim1, wherein the inserts are mounted in openings, which are provided forsaid inserts, in transverse bars of the frame.
 7. Transport device, asclaimed in claim 1, further comprising, at least one drive mechanism forrotating the inserts.
 8. Loading and unloading device, in combinationwith the transport device of claim 1, comprising at least onemanipulator for grasping the at least one retainer bar and a drive unitfor moving the at least one retainer bar in a plane formed by the frameand/or in a direction normal to the plane.
 9. Loading and unloadingdevice, as claimed in claim 8, wherein the at least one manipulator hasat least one gripper claw for grasping the at least one retainer bar.10. Loading and unloading device, as claimed in claim 9, wherein the atleast one gripper claw has an operator fork and a holding down device,which interacts with the operator fork.
 11. Loading and unloadingdevice, as claimed in claim 8, further comprising at least one moveablestorage device for feeding substrates to the transport device or forcarrying substrates away from the transport device.
 12. Loading andunloading device, as claimed in claim 8, further comprising at least onemoveable lifting device for lifting and supporting inserts in thedirection normal to the plane formed by the frame.